1. Field of the Invention
The present invention relates to an additive for roller compacted concrete pavement. Particularly, it relates to additives for improving the pavement properties of roller compacted concrete and mortar.
2. Description of the Prior Art
A roller compacted pavement which has been recently spread can ideally use concrete with zero slump. This is significantly different in state from a common concrete. The roller compacted pavement, in order to accomplish zero slump, must drastically reduce the content of water contained in its concrete, and as a result the rate of packing of the concrete is decreased during the period from the initial mixing of the starting material to the application of the concrete. Evaporation of water due to heat of hydration and sun irradiation, reduces the strength of the resulting concrete and the resulting cured concrete often cracks. This problem often occurs in summer laying of roller compacted pavement.
Further, the thickness of the layer produced by a roller compacted pavement can not be more than 30 cm, because of the difficulty of packing of the concrete. When heavy pavement having more than 30 cm in thickness is required because of heavy traffic situations, double layering must be used. In this situation, there is an inherent weakness in the adhere strength between the layers.
In the conventional process of relaying a roller compacted pavement, it is difficult to control the content of water concrete in the pavement, and/or the packing of the concrete for laying the roller compacted concrete pavement.